Devices configured to sense pressure are needed not only for home safety devices but also in a variety of applications using body pressure distributions. A typical pressure sensor includes a lower electrode, a middle layer disposed on the lower electrode, and an upper electrode disposed on the middle layer.
Since a thickness of the middle layer, which is a piezoresistive layer, is decreased due to an external pressure, the above-described pressure sensor may detect an applied pressure based on a variation in thickness of the middle layer. Particularly, a force sensing register (FSR) sensor, which is a thin-film-type pressure sensor, is difficult to scale up, and has reduced flexibility because conductive interconnections are printed on a thin film. Accordingly, a sheet-type pressure sensor has lately been developed.
FIG. 1 is a photograph of a typical sheet-type pressure sensor.
As shown in FIG. 1, since the typical sheet-type pressure sensor is manufactured by separately forming first and second electrode layers 5a and 5c and a middle layer 5b and adhering the first and second electrode layers 5a and 5c and the middle layer 5b to each other, manufacturing costs may increase and alignment problems may occur.